Coupling for caravans and trailers

ABSTRACT

A coupling for a caravan or trailer has a body for mounting on the caravan or trailer tow-bar, and a shaft, with a coupling socket at its front, slidable through the ball of a ball and socket joint in the front of the body, so the shaft may be extended, until stopped by an enlarged rear-end piece, or retracted. The body is shaped so that when the shaft is extended, its coupling socket may be swung to either side or up or down, and when the shaft is retracted the rear-end piece is guided to, and releasably engaged by, a lock.

United States Patent 191 Everin ham Feb. 26, 1974 COUPLING FOR CARAVANSAND 1,422,189 7/1922 Eckertz 280/478 AR TRAILERS FOREIGN PATENTS ORAPPLICATIONS Inventor: Leslie Everingham, New South 661,773 6/1938Germany 280/478 A Wales, Australia, 839,387 6/1960 Great Britain 280/478B [73] Assignee: Alexander Papp, Tweed Heads, New I South wales,Australia; a part Primary ExammerLeo Frlaglla interest AssistantExaminer-Randall A. Schrecengost Attorney, Agent, or Firm-Donald D.Jeffery [22] F1led: Aug. 8, 1972 [21] Appl. No.: 278,822 [57] ABSTRACT Acoupling for a caravan or trailer has a body for [30] ForeignApplication Priority Data mounting on the caravan or trailer tow-bar,and a Aug. 10,1971 Australia 5850/71 Shaft, with a Coupling Socket atits from, Slidable through the ball of a ball and socket joint in thefront 52 11.8. C1 280/478 R of the body, so the Shaft y be extended,until 51 Int. Cl B60d 1/04 pp y a enlarged rear-end p or re r c ed. [58]Field of Search 280/482, 491,478 The y is shaped so that when the shaftis extended, its coupling socket may be swung to either side or up 5References (m or down, and when the shaft is retracted the rear-endUNITED STATES PATENTS Conrad 280/478 RR piece is guided to, andreleasably engaged by,a lock.

2 Claims, 3 Drawing Figures PATENTED FEB 2 6 I974 SHEET. 1 0F 2 COUPLINGFOR CARAVANS AND TRAILERS This invention relates to an improved couplingfor caravans and trailers.

A good deal of difficulty is commonly experiencedin coupling a caravanor the like to a car which is to tow it. The car must be backedsufficiently close to the caravan so that the female member or socket ofthe ball and socket coupling device fitted to the caravan can be easilyengaged with the male or ball member of the coupling secured to the towbar of the car, and to position the car so that the connection canbe'made without great difficulty is often difficult and time consuming.

The general object of the present invention is to provide a couplingdevice for use with a caravan, trailer or the like whereby effectingsuch a connection is very greatly simplified.

According to the invention, a hollow body, which may be welded orotherwise secured on a caravan or trailer drawbar, has at its front aball oscillatable in a socket and formed with a diametral bearing for aslidable shaft which at its front is provided with a coupling socket ofconventional type, for releasable engagement with a coupling ball on thetow bar of a towing vehicle. The shaft, then, may be slidably extendedfrom the housing until an enlarged rear-end piece on the shaft isbrought against the oscillatable ball, and the body is so made that whenthe shaft is fully or partly extended,.its front end, with the couplingsocket, may be swung to either side, raised and lowered, to facilitatethe engagement of the coupling socket with the coupling ball of a towingvehicle. The coupling members being engaged, the towing vehicle may behacked to cause the shaft to be retracted, and guides within the bodydirect its rear-end piece to a lock at the rear of the body, whichautomatically engages the rear-end piece, holding the shaft in retractedposition. A further safety locking device may be engaged with therear-end piece of the shaftby means of a handle, and this handle may beused to release bothlocking means.

In the drawings:

FIG. 1 is a perspective view of a caravan coupling device according tothe invention, the coupling shaft in an extended position,

FIG. 2 is a longitudinal sectional view of the device, the couplingshaft locked in retracted'position, and

FIG. 3 is a rear elevational view, to enlarged scale, of the device withthe rear end plate removed to show the coupling shaft lock.

The device includes a metal body which is a hollow structure consistingof oppositely bowed sides 11 so the body is widest at the middle andrelatively narrow at front and back; a top plate 12; and a bottom plate13, its front part is parallel to the top plate, its rear part incliningupwardly and rearwardly. The body also has a front plate l4v and'a rearplate 15, both perpendicular to the top plate 12, the rear plate 15extending above the top plate and having a rearwardly extending flange16 at its upper end.

The body 10 may be fixedly secured, for example by welding, on the frontpart of the tow-bar assembly of a caravan.

A fore-end plate 17 is bolted to the body front plate 14, and these twoplates have registering central holes of spherical zone shape, the twoapertures forming a socket for-a ball 18. A coupling shaft 19' isslidable through a diametral passage through the ball, and has mountedon its front end a generally conventional coupling socket assembly 20capable of being releasably locked in engagement with a coupling ball(not shown) mounted behind a towing vehicle. Behind the socket assembly20, a helical compression spring 21 is fitted about the coupling shaft19. A curved flange 22, having a rib 23 secured transversely across it,extends rearwardly of the socket assembly 20 to cover part of the spring21.

On the rear end of the coupling shaft 19 is a rear-end piece 24consisting of a cylindrical front section coaxial with and of greaterdiameter than the shaft, and a rear section tapering to a point.

The coupling socket assembly 20 may be drawn forwardly from the body 10until the rear-end piece 24 is brought to the ball 18, and the assemblywhen extended may be swung to one side or the other, and raised orlowered. If the socket assembly 20 is pushed rearwardly relative to thebody 10, the rear-end piece 24 is guided by the side plates 11 and thetop and bottom plates 12 and 13 to bring it to an opening 25 in the rearplate 15, through which the rear-end piece can freely pass, to beautomatically engaged by. a lock.

- The lock, as shown particularly in FIG. 3, includes an upper lockingpiece 26 and a lower locking piece 27, both vertically slidable againstthe rear of the end plate 15 and between a pair of upright guides 28.The locking pieces are retained in place between the guides by arear-end plate 29 bolted to the guides 28, and having a tubularrearwardly extending housing 30 the bore of which is co-axial with andof about the same diameter as the opening 25 through the rear plate 15.Formed integrally with the plate 29 and housing 30 are a rearwardlyextending rack. arm 31 and a pair of down- J wardly and rearwardlyinclining apertured lugs 32. In

known manner, a hand-lever (not shown) for the handbrake of the caravanmay be fulcrumed between the apertured lugs 32, being fitted with a pawlreleasably engageable with the rack 31, and with a projection whichmayextend towards the bore of the housing 30.

The upper locking piece 26 is notched from its lower edge, the lowerlocking piece 27 is notched from its upper edge, so that when the twoare brought together the two notches will fit closely about the couplingshaft 19 in front of its rear-end piece 24. As shown in FIGS. 2 and 3,the lower locking piece 27 is in lowermost position, resting on a stop33 on the back plate 15. A lug 34 extending downwardly from the lowerlocking piece 27 is transversely apertured to receive a shaft 35 securedbetween the lower ends of a pair of links 36, of which the lower partsare upright, the upper parts including upwardly to the rear. The upperends of the links are connected by a shaft 37, on which are pivotedthe'front ends of a pair of short levers 38 secured at opposite sides ofone end of a handle 39. Between the rear ends of the short levers 38there is pivoted a head 40 of a spindle 41 extending upwardly from upperlocking piece 26 through the flange 16 of back plate 15 and having anadjustment nut 42 engaged thereon above the flange. A helicalcompression spring 43 on the spindle between the upper locking piece andthe flange l6 urges the upper locking piece 26 to lowered position, asshown particularly in FIG. 3, covering the upper part of the passage 25through the back plate 15. However, when the coupling shaft 19 is forcedrearwardly relative to the body 10, the pointed end of the rear-endpiece 3 24 will force the upper locking piece 26 upwardly against theaction of the spring 43 until, the rear-end piece 24 having moved torearmost position, the upper locking piece is free to descend, retainingthe rear-end piece behind the said locking piece.

The lower locking piece 27 may be raised to operative position, closelyengaging the lower part of the coupling shaft 19 in front of therear-end piece 24, by swinging the handle 39 forwardly and down to liftthe links 36. By inserting a pin (not shown) through an apertured lug 44on the handle 39 and through an apertured arm 45 secured to andextending upwardly from the body top plate 12, the lock may be heldengaged.

A swinging stop 46 is pivoted about a longitudinal axis to an upperfront corner of the body for a purpose hereinafter described.

In use, when a towing vehicle is to be backed to be coupled to thecaravan, the lock is disengaged to free the coupling shaft 19. This isdone by disconnecting the apertured lug 44 of the handle 39 from theapertured arm 45 and swinging the handle upwardly and rearwardly tocause the links 36 to lower the lower locking piece 27; and by swingingthe handle 39 further rearwardly to cause the spindle 41 to be lifted bythe short levers 38 to raise the upper locking piece 26. The couplingsocket assembly may then be drawn forwardly,

, the rear-end piece 24 of the coupling shaft 19 passing freely throughthe passage into the body 10. The coupling socket assembly 20 may beadvanced, retracted, raised, lowered, turned about the axis of the shaft19, or swung to one side or the other, as may be required to facilitateits engagement with the coupling ball on the towing vehicle. When thisis done, the towing vehicle may be backed, causing the coupling shaft 19to be moved rearwardly through the ball 18 and the body 10 until itsrear-end piece 24 passes through the passage 25 of the rear plate 15 andis engaged automatically by the upper locking piece 26, the spring 21 onthe coupling shaft 19 being somewhat compressed. The handle 39 is thenswung down to the body 10, to lift the lower locking piece 27 tooperative position, the handle then being secured in this position asbefore described.

The caravan may then be towed away in usual manner. lfthe towingvehicle, while travelling, is braked, so that the caravan tends byinertia to exert compression on the shaft 19, the spring 21 is furthercompressed and the rear-end piece 24 co-acts with the caravan brakelever pivoted between the lugs 32 in known manner to cause the caravanbrakes to be applied.

When the caravan is to be backed by the towing vehicle, the swingingstop 46 is swung from inoperative position, as shown in FIG. 1, tooperative position overlying the rear part of the curved flange 22 andclose to the transverse rib 23, to prevent the caravan brake from beingapplied by compression applied to the shaft 19 by the reversing vehicle.

What I claim is:

1. A coupling for caravans and trailers including:

a hollow body adapted to be mounted on a tow bar of a caravan ortrailer,

a bearing mounted for oscillation in the front of the body,

a shaft slidable through the bearing to extended and retractedpositions, the front of the shaft being movable laterally and verticallywhen the shaft is in extended position,

a coupling socket on the front of the shaft,

a rear-end piece on the rear of the shaft, limiting the extension of theshaft through the bearing,

a lock at the rear end of the body, engageable with the rear-end piece,

said lock comprising a spring-loaded first locking piece automaticallyengageable with the rear-end piece when the shaft is retracted, a secondlocking piece, and a handle connected to the first and second lockingpieces and adapted, when moved to operative position, to move the secondlocking piece into engagement with the rear-end piece, and when moved toinoperative position to move the first and second locking pieces out ofengagement with the rear-end piece, and

guides in the body directing the rear-end piece, when the shaft isretracted, to the lock.

2. A coupling apparatus for caravans and trailers including:

a hollow body adapted to be mounted on a tow bar of a caravan ortrailer,

a bearing mounted for oscillation in the front of said body, I

a shaft slidable through said bearing to extended and retractedpositions, the front of said shaft being movable laterally andvertically when said shaft is in said extended position,

coupling means on the front of said shaft for coupling said apparatus toa vehicle,

a rear-end piece on the rear portion of said shaft for limiting theextension of said shaft'through said bearing, and

lock means releasably engageable with said rear-end piece of said shaftandmount ed at the rear portion of said body, said lock means comprisinga first locking member which is resiliently biased so as toautomatically engage said rear-end piece when said shaft is retracted, asecond locking member opposed to said first locking member, andoperating means connected to said first and second locking memberswhich, when moved to a first position, will move said second lockingmember into engagement with said rear-end piece thereby locking saidshaft, and which, when moved to a second position, will move both saidfirst and second locking members out of engagement with said rear-endpiece to free said shaft.

1. A coupling for caravans and trailers including: a hollow body adaptedto be mounted on a tow bar of a caravan or trailer, a bearing mountedfor oscillation in the front of the body, a shaft slidable through thebearing to extended and retracted positions, the front of the shaftbeing movable laterally and vertically when the shaft is in extendedposition, a coupling socket on the front of the shaft, a rear-end pieceon the rear of the shaft, limiting the extension of the shaft throughthe bearing, a lock at the rear end of the body, engageable with therear-end piece, said lock comprising a spring-loaded first locking pieceautomatically engageable with the rear-end piece when the shaft isretracted, a second locking piece, and a handle connected to the firstand second locking pieces and adapted, when moved to operative position,to move the second locking piece into engagement with the rear-endpiece, and when moved to inoperative position to move the first andsecond locking pieces out of engagement with the rear-end piece, andguides in the body directing the rear-end piece, when the shaft Isretracted, to the lock.
 2. A coupling apparatus for caravans andtrailers including: a hollow body adapted to be mounted on a tow bar ofa caravan or trailer, a bearing mounted for oscillation in the front ofsaid body, a shaft slidable through said bearing to extended andretracted positions, the front of said shaft being movable laterally andvertically when said shaft is in said extended position, coupling meanson the front of said shaft for coupling said apparatus to a vehicle, arear-end piece on the rear portion of said shaft for limiting theextension of said shaft through said bearing, and lock means releasablyengageable with said rear-end piece of said shaft and mounted at therear portion of said body, said lock means comprising a first lockingmember which is resiliently biased so as to automatically engage saidrear-end piece when said shaft is retracted, a second locking memberopposed to said first locking member, and operating means connected tosaid first and second locking members which, when moved to a firstposition, will move said second locking member into engagement with saidrear-end piece thereby locking said shaft, and which, when moved to asecond position, will move both said first and second locking membersout of engagement with said rear-end piece to free said shaft.